Mismatch gauge



July 15, 1958 F H. JOHNSON MISMATCH GAUGE Filed Nov. 17, 1954 lman for f H@Zm&7 (10/706022 United States Patent MISMATCH GAUGE F Helmer Johnson, Rockford, 11]., assignor'to Rockford Drop Forge Co., Rockford, 111., a corporation of Illi- 11015 Application November 17, 1954, Serial No. 469,403

9 Claims. (Cl. 33-172) In other words, it is any displacement in a plane parallel to the main or fundamental parting plane of the dies. Mismatching tolerances are independent of and in addition to any other tolerances. The following table serves to show what tolerances are acceptable generally for commercial work and close work:

MISMATCHING TOLERANCES (Inches) Net weight up topounds Commercial Close It is the principal object of my invention to provide a hand operable gauge adapted for quickly but accurately checking alignment in closed die forgings having equal proportions on each side of the parting line, the gauge being so designed that it may be used just as conveniently before as after the flash has been removed from the forgings, the present gauge being one especially designed for checking forgings having opposed flat parallel surfaces, such as connecting rods, for example, where the matter of both side shift and end shift on the crank end and pin end requires checking.

The invention is illustrated in the accompanying drawing, in which Figs. 1 and 2 are an edgewise view and side view, respectively, of a mismatch gauge made in accordance with my invention, Fig. 2 illustrating the operation of the gauge, correct die alignment being indicated by the full line position of the indicator finger and a shift or mismatch by the dotted line position.

The same reference numerals are applied to corresponding parts in the two views.

Referring to the drawing, the reference numerals 3 and 4 designate the two elongated body members of the gauge which provide work engaging jaws 5 and 6, respectively, on one end and operating handles 7 and 8, respectively, on the other end, these being designed to be held in the one hand of the operator. The toggle linkages 910 interconnecting the body members 3 and 4 on opposite sides maintain absolute parallelism of the jaws 5 and 6 in all positions of adjustment of the handles 7 and 8 toward and away from one another so that the jaws can be engaged accurately on the parallel top and bottom surfaces 11 and 12 of a forging 13, as appears in Fig. 2, the particular portion of the forging indicated being one end portion of a connecting rod forging. Each of the links 9 is pivotally connected at one end, as at 14,

to the body member 3 and slidably pivotally connected at the other end, as at 15, in a longitudinal slot 16 in the other body member 4, while each of the links 10 is pivotally connected at one end, as at 17, to the body member 4 with a spacer washer 18 therebetween and is slidably pivotally connected at the other end, as at 19, to the body member 3 in a longitudinal slot 20 provided therein, a spacer washer 21 being provided at that end also. The links 9 and 10 have their middle portions pivotally connected together, as at 22.

A rigid stop projection 23 is provided at the inner end of the jaw 5 for abutment with the inclined side 24 of the upper half of the forging to be checked. The jaw 6, however, has a movable feeler 25 associated therewith and located at the inner end thereof for abutment with the inclined side 26 of the lower half of the forging to be checked, the feeler 25 being formed on one end of an L-shaped indicator finger 27 that is pivotally mounted at 28 on one side of the body member 4 at the inner end of the jaw 6, and the other end of the finger being pointed, as indicated at 29, for cooperation with graduations 30 provided on an arcuate extension 31 provided on the jaw member 4. A coiled tension spring 32, which is anchored at one end, as at 33, to the jaw member 4, is attached at its other end, as at 34, to the indicator finger 27 to urge it in a counterclockwise direction, as viewed in Fig. 2,

In operation, when there is no shift or mismatch found in a'forging the indicator finger 27 points to the zero mark 35, as shown in full lines in Fig. 2. However, if

'the indicator finger deviates from the zero mark more than one graduation line either way it indicates mismatching of more than & inch which is not acceptable for commercial forgings having a net weight up to one pound, as shown in the table' above, so that the forging would have to be rejected and attention given the dies promptly to avoid further waste and dollar loss. Side shift is checked in a direction at right angles to the longitudinal center line of the connecting rod, end shift in a direction along said center line. The finger 27 is elongated enough to give about 8 to 1 multiplication so that the graduation lines 30 can be spaced apart far enough for quick and easy reading of the gauge. It is obvious that the jaws 5 and 6 may be opened much farther'than is shown in Fig. 2 to admit larger size forgings. The flash shown at 36 on the forging 13 obviously does not interfere at all with'the operation of the gauge and that, of course, is quite a convenience and means a substantial saving as it obviates the necessity for removing the flash from forgings that might later turn out to be rejects.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims have been drawn to cover all legitimate modifications and adaptations.

I claim:

1. A mismatch gauge comprising a pair of relatively movable jaws having parallel inner surfaces between which a forging to be checked for shift or mismatch is placed, means maintaining parallel relationship of said surfaces in the opening and closing movements of the jaws, a stop projection on one of said jaws arranged to engage a side surface on the forging being checked, at feeler projecting from the other of said jaws and engageable with another portion of the forging on the same side engaged by said projection, said feeler being movably mounted with respect to a graduated scale in fixed relation to the last mentioned jaw, and spring means urging said feeler toward engagement with the part placed between the jaws.

2. A mismatch gauge comprising a pair of relatively movable jaws having parallel inner surfaces between which a forging to be checked for shift or mismatch is placed, means maintaining parallel relationship of said surfaces in the opening and closing movements of the jaws, a stop projection onone of said jaws arranged to engage a side surface on the forging being checked, a feeler projecting from the other jaw for engagement with the forging on the same side with said projection, said feeler being pivoted with respect to said jaw and operating a pointer relative to a graduated scale in fixed relation to the last mentioned jaw, and spring means urging said feeler toward engagement with the forging placed between the jaws.

3. A mismatch gauge comprising a pair of relatively movable jaws having parallel inner surfaces between which a forging to be checked for shift or mismatch is placed, means maintaining parallel relationship of said surfaces in the opening and closing movements of the jaws, a stop projection on one of said jaws arranged to engage a side surface on the forging being checked, a feeler projecting from the other jaw for engagement with the same side of the forging with said projection, said feeler constituting one leg of an L-shaped indicator finger pivoted on said last mentioned jaw, the other leg of the L being elongated and terminating in a pointer movable relative to a graduated scale supported in fixed relation to said last mentioned jaw, and spring means urging said indicator finger in one direction so that the feeler is urged toward the forging disposed between the aws.

4. A gauge of the character described comprising a pair of relatively movable jaws having parallel inner surfaces for engagement on opposite sides of a part to be gauged, means maintaining parallel relationship of said surfaces in the opening and closing of the jaws, a stop projection on one of said jaws arranged to engage a side surface on the part being gauged, a feeler projecting from the other of said jaws for engagement with another portion of the part being gauged on the same side thereof engaged by said projection, said feeler being movably mounted with respect to a graduated scale in fixed relation to the last mentioned jaw, and spring means urging said feeler toward engagement with the part placed between the jaws.

5. A gauge of the character described comprising a pair of relatively movable jaws having parallel inner surfaces for engagement on opposite sides of a part to be gauged, means maintaining parallel relationship of said surfaces in the opening and closing of the jaws, a stop projection on one of said jaws arranged to engage a side surface on the part being gauged, a feeler projecting from the other jaw for engagement with the part being gauged on the same side engaged by said projection, said feeler being pivoted with respect to said last mentioned jaw and operating a pointer relative to a graduated scale in fixed relation to the last mentioned jaw, and spring means urging said feeler toward engagement with the part placed between the jaws.

6. A gauge of the character described comprising a pair of relatively movable jaws having parallel inner surfaces for engagement on opposite sides of a part to be gauged, means maintaining parallel relationship of said surfaces in the opening and closing of the jaws, a stop projection on one of said jaws arranged to engage a side surface on the part being gauged, a feeler projecting from the other jaw for engagement with the part being gauged on the same side engaged by said projection, said feeler constituting one leg of an L-shaped indicator finger pivoted on said last mentioned jaw, the other leg of the L being elongated and terminating in a pointer movable relative to a graduated scale in fixed relation to the last mentioned jaw, and spring means urging said indicator finger in one direction to engage the feeler with the part placed between the jaws.

7. A gauge as set forth in claim 4, wherein the graduated scale has a zero mark approximately at the middle thereof which the feeler indicates when the feeler engages a perfect part, the feeler being movable one way from the zero mark on the scale for an out-of-true condition of the part one way, and vice versa.

8. A gauge as set forth in claim 5, wherein the graduated scale has a zero mark approximately at the middle thereof which the pointer indicates when the feeler engages a perfect part, the pointer being movable one way from the zero mark on the scale for an out-of-true condition of the part one way, and vice versa.

-9. A gauge as set forth in claim 6, wherein the graduated scale has a zero mark approximately at the middle thereof which the pointer indicates when the feeler engages a perfect part, the pointer being movable one way from the zero mark on the scale for an out-of-true condition of the part one way, and vice versa.

References Cited in the file of this patent UNITED STATES PATENTS 2,581,219 Thorburn Jan. 1, 1952 2,591,314 Stelmach Apr. 1, 1952 FOREIGN PATENTS 54,399 Norway Apr. 25, 1923 

